Imaging lens assembly

ABSTRACT

An imaging lens assembly is provided in the present disclosure. The imaging lens assembly includes a first lens with positive refractive power, a second lens with negative refractive power, a third lens with positive refractive power, a forth lens with positive refractive power and a fifth lens with negative refractive power, the first lens, the second lens, the third lens, the forth lens and the fifth lens are arranged in sequence from the object side to the image side, and satisfy the conditions provided in the present disclosure.

FIELD OF THE DISCLOSURE

The present disclosure relates to optical technologies, and moreparticular, to an imaging lens assembly applicable to a digital cameraof a mobile phone or a WEB camera, which uses CCD imaging components orCMOS imaging components with high resolution.

BACKGROUND

CCD imaging components and CMOS imaging components are used widely incamera device, to meet the requirements of miniaturization and goodperformance of the imaging components, a wide-angle lens assembly withgood optical characteristic, less thickness, and high luminous flux(namely, F Number) is needed.

Japanese patent No. 5513641 discloses an imaging lens assembly includingfive lenses. However, as the shapes of the first lens, the second lensand the fifth lens are inadequate, the proportion of the total tracklength (TTL) and the image height (IH) of the imaging lens assembly isgreater than 1.58; this is, TTL/IH≧1.58. Accordingly, the imaging lensassembly is too thick to meet the miniaturization requirement.

In addition, Japanese patent No. 5775983 discloses an imaging lensassembly including five lenses. However, as the shapes of the first lensand the second lens are inadequate, the proportion value TTL/IH of theimaging lens assembly is greater than 1.34; this is, TTL/IH≧1.34.Accordingly, the imaging lens assembly is too thick to meet theminiaturization requirement.

Accordingly, an improved imaging lens assembly which can overcome thedisadvantages described above is desired.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiment can be better understood with referenceto the following drawings. The components in the drawing are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the present disclosure. Moreover,in the drawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a structural diagram of an imaging lens assembly related to anembodiment of the present disclosure;

FIG. 2 is a structural diagram of the imaging lens assembly inaccordance with the first embodiment of the present disclosure;

FIG. 3 is the longitudinal aberration of the imaging lens assembly ofFIG. 2;

FIG. 4 is the lateral color of the imaging lens assembly of FIG. 2;

FIG. 5 is the field curvature and distortion of the imaging lensassembly of FIG. 2;

FIG. 6 is a structural diagram of the imaging lens assembly inaccordance with the second embodiment of the present disclosure;

FIG. 7 is the longitudinal aberration of the imaging lens assembly ofFIG. 6;

FIG. 8 is the lateral color of the imaging lens assembly of FIG. 6;

FIG. 9 is the field curvature and distortion of the imaging lensassembly of FIG. 6.

DETAILED DESCRIPTION

The present invention will hereinafter be described in detail withreference to several embodiments.

Referring to FIG. 1, an imaging lens assembly LA according to anembodiment of the present disclosure is shown. The imaging lens assemblyLA includes a lens set with five lenses, that is, a first lens L1, asecond lens L2, a third lens L3, a forth lens L4 and a fifth lens L5,which are arranged in order from the object side to the image side. Aglass filter GF is arranged between the fifth lens L5 and an imageplane, the glass filter GF may be a cover glass or an IR filter plate.Alternatively, the glass filter GF may be arranged in other locations oreven removed from the imaging lens assembly LA.

The first lens L1 has a positive refractive power, the second lens L2has a negative refractive power, the third lens L3 has a positiverefractive power, the forth lens L4 has a positive refractive power, andthe fifth lens L5 has a negative refractive power. In practice, thefifth lens L5 is designed to have aspheric surfaces, so as to compensateaberration in the imaging lens assembly LA.

The imaging lens assembly LA as provided in the present embodimentsatisfies the following conditions (1) to (3):

0.08≦R1/R2≦0.25  (1)

−5.00≦R3/R4≦−0.30  (2)

−1.50≦R9/R10≦−0.30  (3)

In the above conditions (1) to (3),

R1 is the curvature radius of the object side of the first lens L1;R2 is the curvature radius of the image side of the first lens L1;R3 is the curvature radius of the object side of the second lens L2;R4 is the curvature radius of the image side of the second lens L2;R9 is the curvature radius of the object side of the fifth lens L5; andR10 is the curvature radius of the image side of the fifth lens L5.

The condition (1) defines the shape of the first lens L1. If theproportion value R1/R2 is beyond the value range defined in condition(1), it is difficult to compensate the high order aberrations such asthe spherical aberration when the imaging lens assembly LA has a lessthickness and a wider view angle with an F number (Fno) less than 2.2.

In addition, the proportion value R1/R2 in condition (1) is preferred tobe set in the value range as defined in the following condition (1-A):

0.10≦R1/R2≦0.18  (1-A)

The condition (2) defines the shape of the second lens L2. If theproportion value R3/R4 is beyond the value range defined in condition(2), it is difficult to compensate on-axis aberration and off-axisaberration when the imaging lens assembly LA has a less thickness and awider view angle with an F number (Fno) less than 2.2.

In addition, the proportion value R3/R4 in condition (2) is preferred tobe set in the value range as defined in the following condition (2-A):

−2.00≦R3/R4≦−1.00  (2-A)

The condition (3) defines the shape of the fifth lens L5. If theproportion value R9/R10 is beyond the value range defined in condition(3), an axial distance between the image side of the fifth lens L5 andthe image plane may not be assured in the imaging lens assembly LA whenthe imaging lens assembly LA has a less thickness and a wider view anglewith an F number (Fno) less than 2.2.

In addition, the proportion value R9/R10 in condition (3) is preferredto be set in the value range as defined in the following condition(3-A):

−0.70≦R9/R10≦−0.50  (3-A)

The third lens L3 has a positive refractive power, and satisfies thefollowing conditions (4) and (5):

10.00≦f3/f≦70.00  (4)

0.65≦R5/R6≦1.05  (5)

In the above conditions (4) and (5),

f is the focal length of the imaging lens assembly LA;f3 is the focal length of the third lens L3;R5 is the curvature radius of the object side of the third lens L3; andR6 is the curvature radius of the image side of the third lens L3.

The condition (4) defines the positive refractive power of the thirdlens L3. If the proportion value f3/f is beyond the value range definedin condition (4), it is difficult to compensate the off-axis chromaticaberration when the imaging lens assembly LA has a less thickness.

The condition (5) defines the shape of the third lens L3. If theproportion value R5/R6 is beyond the value range defined in condition(5), it is difficult to compensate the off-axis chromatic aberrationwhen the imaging lens assembly LA has a less thickness and a wider viewangle with an F number (Fno) less than 2.2.

In addition, the proportion value R5/R6 in condition (5) is preferred tobe set in the value range as defined in the following condition (5-A):

0.70≦R5/R6≦0.95  (5-A)

Upon the condition that the first lens L1, the second lens L2, the thirdlens L3, the forth lens L4 and the fifth lens L5 satisfy the aforesaidconditions, the imaging lens assembly LA is possible to have goodoptical characteristic as well as an ultra-thin profile, and moreover,the imaging lens assembly LA may also satisfy the following parameterrequirements: TTL/IH≦1.30, view angle 2ω≧80°, and Fno≦2.2.

The following description describes the imaging lens assembly LAaccording to the present disclosure in detail with reference to severalembodiments; parameters of the imaging lens assembly are defined asfollows, in which the unit of each of distance, radius, and centralthickness is millimeter (mm):

f: the focal length of the imaging lens assembly LA;f1: the focal length of the first lens L1;f2: the focal length of the second lens L2;f3: the focal length of the third lens L3;f4: the focal length of the forth lens L4;f5: the focal length of the fifth lens L5;

Fno: F-number;

2ω: full view angle;S1: aperture stop;R: a curvature radius of an optical surface, and may also be a centralcurvature radius of a lens;R1: the curvature radius of the object side of the first lens L1;R2: the curvature radius of the image side of the first lens L1;R3: the curvature radius of the object side of the second lens L2;R4: the curvature radius of the image side of the second lens L2;R5: the curvature radius of the object side of the third lens L3;R6: the curvature radius of the image side of the third lens L3;R7: the curvature radius of the object side of the forth lens L4;R8: the curvature radius of the image side of the forth lens L4;R9: the curvature radius of the object side of the fifth lens L5;R10: the curvature radius of the image side of the fifth lens L5;R11: the curvature radius of the object side of the glass filter GF;R12: the curvature radius of the object side of the glass filter GF;d: an central thickness of the lens or an axial distance between lenses;d0: the axial distance between the aperture stop S1 and the object sideof the first lens L1;d1: the central thickness of the first lens L1;d2: the axial distance between the image side of the first lens L1 andthe object side of the second lens L2;d3: the central thickness of the second lens L2;d4: the axial distance between the image side of the second lens L2 andthe object side of the third lens L3;d5: the central thickness of the third lens L3;d6: the axial distance between the image side of the third lens L3 andthe object side of the forth lens L4;d7: the central thickness of the forth lens L4;d8: the axial distance between the image side of the forth lens L4 andthe object side of the fifth lens L5;d9: the central thickness of the fifth lens L5;d10: the axial distance between the image side of the fifth lens L5 andthe object side of the glass filter GF;d11: the central thickness of the glass filter GF;d12: the axial distance between the image side of the glass filter GFand the image plane;nd: d line refraction index;n1: d line refraction index of the first lens L1;n2: d line refraction index of the second lens L2;n3: d line refraction index of the third lens L3;n4: d line refraction index of the forth lens L4;n5: d line refraction index of the fifth lens L5;n6: d line refraction index of the glass filter GF;νd: abbe number (i.e., dispersion coefficient)ν1: abbe number of the first lens L1;ν2: abbe number of the second lens L2;ν3: abbe number of the third lens L3;ν4: abbe number of the forth lens L4;ν5: abbe number of the fifth lens L5;ν6: abbe number of the glass plate GF;TTL: the total track length (i.e., an axial distance between the objectside of the first lens L1 and the image plane);LB: the axial distance between the image side of the fifth lens L5 andthe image plane (including the thickness of the glass plate GF); andIH: the image height.

y=(x ² /R)/[1+{1−(k+1)(x ² /R ²)}^(1/2) ]+A4x ⁴ +A6x ⁶ +A8x ⁸ +A10x ¹⁰+A12x ¹² +A14x ¹⁴ +A16x ¹⁶  (6)

In the above condition (6), R is the axial curvature radius, k is theconic coefficient, and A4, A6, A8, A10, A12, A14 and A16 are asphericalcoefficients.

Optionally, aspherical surfaces of the lenses L1-L5 may be obtainedaccording to condition (6); alternatively, the aspherical surfaces mayalso be obtained according to other conditions.

Embodiment 1

FIG. 2 illustrated an imaging lens assembly LA in accordance with thefirst embodiment of the present disclosure. TABLE 1 and TABLE 2 show thedetailed optical data of the imaging lens assembly LA.

The optical data in TABLE 1 includes the curvature radius R, the centralthickness d, the axial distance d between lenses, refraction index ndand abbe number νd of the lenses L1-L5 in the imaging lens assembly LA.

The optical data in TABLE 2 includes conic coefficient (C-coefficient) kand aspherical coefficient of the lenses L1-L5 in the imaging lensassembly LA.

TABLE 1 R d nd νd S1 ∞ d0 = −0.210 R1 1.12491 d1 = 0.483 nd1 1.5441 ν156.12 R2 7.61015 d2 = 0.079 R3 −7.69938 d3 = 0.199 nd2 1.6422 ν2 22.41R4 5.35662 d4 = 0.253 R5 8.22718 d5 = 0.202 nd3 1.6422 ν3 22.41 R611.11744 d6 = 0.432 R7 −3.56285 d7 = 0.470 nd4 1.5441 ν4 56.12 R8−1.10357 d8 = 0.409 R9 −1.72267 d9 = 0.310 nd5 1.5352 ν5 56.12 R103.03581 d10 = 0.400 R11 ∞ d11 = 0.210 nd6 1.5168 ν6 64.17 R12 ∞ d12 =0.288

TABLE 2 C-coefficient aspherical coefficient k A4 A6 A8 A10 A12 A14 A16R1 0.0000E+00 −8.2623E−03 1.2189E−01 −2.4013E−01 −1.5752E−01 4.3467E−019.4646E−01 −1.9429E+00 R2 0.0000E+00 −4.9581E−02 −3.5808E−02 3.3460E−01−1.5252E−01 −1.5352E+00 −2.4879E−00 −1.7228E+00 R3 0.0000E+00 7.1731E−021.6497E−01 6.1642E−02 −1.0402E−02 −6.0268E−01 −4.1321E−00 6.6338E+00 R44.6998E+01 1.4771E−01 1.8550E−01 2.8288E−01 6.3614E−02 −1.2325E+00−2.3171E−01 6.3813E+00 R5 −1.0748E+01 −2.6723E−01 9.1523E−02 1.0734E−01−1.6313E−02 2.9287E−01 4.8790E−01 −1.5905E+00 R6 1.4608E+02 −2.0219E−01−3.2654E−02 9.0312E−02 1.2098E−01 9.1563E−02 3.3334E−03 −2.6678E+01 R77.3348E+00 −5.2239E−03 1.5559E−02 −3.6949E−01 1.5112E−03 4.3701E−034.6458E−03 4.2487E+03 R8 −3.5756E+00 −5.7233E−02 7.7914E−02 −3.8471E−023.5527E−03 −3.8246E−04 7.5333E−04 −2.1348E+04 R9 −4.1573E+00 −3.4951E−021.2774E−02 5.1979E−04 −2.8607E−04 −1.6272E−05 −2.1661E−06 1.4985E+06 R10−5.3959E+01 −5.7688E−02 1.4071E−02 −4.0478E−03 4.0001E−04 −3.3152E−052.6534E−07 −1.3450E+06

The relevant optical data of the imaging lens assembly LA in the firstembodiment and the values defined in the aforesaid conditions (1) to (5)are shown in TABLE 5 as provided in the subsequent paragraphs.

As can be seen in TABLE 5, the imaging lens assembly LA in the firstembodiment satisfies the aforesaid conditions (1) to (5).

FIGS. 3-5 schematically illustrate the longitudinal aberration, thelateral color, the field curvature and distortion of the imaging lensassembly LA as provided in the first embodiment respectively. In FIG. 5,curve S represents the field curvature related to the sagittal plane,and curve T represents the field curvature related to the tangentialplane.

As can be seen, in the first embodiment, the view angle 2ω of theimaging lens assembly LA is 80.8°, the proportion value TTL/IH of theimaging lens assembly LA is 1.270, and the F-number (Fno) is 2.2. Inother words, the imaging lens assembly LA as provided in the firstembodiment has a wide view angle and is small-size with high luminousflux, and accordingly has good optical characteristics.

Embodiment 2

FIG. 6 illustrated an imaging lens assembly LA in accordance with thesecond embodiment of the present disclosure. TABLE 3 and TABLE 4 showthe detailed optical data of the imaging lens assembly LA in the secondembodiment.

The optical data in TABLE 3 includes the curvature radius R, the centralthickness d, the axial distance d between lenses, refraction index ndand abbe number νd of the lenses L1-L5 in the imaging lens assembly LAaccording to the second embodiment. The optical data in TABLE 4 includesconic coefficient (C-coefficient) k and aspherical coefficient of thelenses L1-L5 in the imaging lens assembly LA according to the secondembodiment.

TABLE 3 R d nd νd S1 ∞ d0 = −0.210 R1 1.12175 d1 = 0.484 nd1 1.5441 ν156.12 R2 7.43158 d2 = 0.079 R3 −7.63249 d3 = 0.193 nd2 1.6422 ν2 22.41R4 5.36073 d4 = 0.251 R5 8.14371 d5 = 0.204 nd3 1.6422 ν3 22.41 R611.14678 d6 = 0.432 R7 −3.56812 d7 = 0.472 nd4 1.5441 ν4 56.12 R8−1.10326 d8 = 0.403 R9 −1.73340 d9 = 0.323 nd5 1.5352 ν5 56.12 R103.03477 d10 = 0.400 R11 ∞ d11 = 0.210 nd6 1.5168 ν6 64.17 R12 ∞ d12 =0.288

TABLE 4 C-coefficient aspherical coefficient k A4 A6 A8 A10 A12 A14 A16R1 0.0000E+00 −8.3374E−03 1.2094E−01 −2.3883E−01 −1.5524E−01 4.3237E−019.4076E−01 −1.9466E+00 R2 0.0000E+00 −5.2183E−02 −3.7054E−02 3.3655E−01−1.4435E−01 −1.5245E+00 −3.6221E−03 1.6714E+00 R3 0.0000E+00 7.2805E−021.6906E−01 6.7909E−02 −1.4710E−02 −6.0243E−01 −4.1429E+00 6.5975E+00 R44.4781E+01 1.5098E−01 2.0329E−01 2.9304E−01 5.3889E−02 −1.2410E+002.2445E−00 6.5725E+00 R5 −1.5763E+01 −2.6823E−01 8.9499E−02 1.0225E−01−1.8381E−02 3.0129E−01 5.1326E−01 −1.6185E+00 R6 1.4518E+02 −2.0269E−01−3.3390E−02 8.8538E−02 1.1717E−01 8.7698E−02 6.2494E−03 −2.5246E+01 R77.3579E+00 −5.1427E−03 −1.5478E−02 −3.6843E−02 1.6135E−03 4.4371E−034.6569E−03 4.2118E+03 R8 −3.5640E+00 −5.7346E−02 7.8024E−02 −3.8420E−023.5752E−03 −3.7450E−04 7.5311E−04 −2.1761E+04 R9 −4.1525E+00 −3.4993E−021.2760E−02 5.1727E−04 −2.8643E−04 −1.6268E−05 −2.1377E−06 1.5092E+06 R10−5.1228E+01 −5.7909E−02 1.4065E−02 −4.0475E−03 4.0005E−04 −3.3160E−052.6077E−07 −1.3428E+06

The relevant optical data of the imaging lens assembly LA in the secondembodiment and the values defined in the aforesaid conditions (1) to (5)are also shown in TABLE 5 as provided in the subsequent paragraphs. Ascan be seen in TABLE 5, the imaging lens assembly LA in the secondembodiment satisfies the aforesaid conditions (1) to (5).

FIGS. 7-9 schematically illustrate the longitudinal aberration, thelateral color, the field curvature and distortion of the imaging lensassembly LA as provided in the second embodiment respectively. In FIG.9, curve S represents the field curvature related to the sagittal plane,and curve T represents the field curvature related to the tangentialplane.

As can be seen, in the second embodiment, the view angle 2ω of theimaging lens assembly LA is 80.8°, the proportion value TTL/IH of theimaging lens assembly LA is 1.272, and the F-number (Fno) is 2.2. Inother words, the imaging lens assembly LA as provided in the secondembodiment has a wide view angle and is small-size with high luminousflux, and accordingly has good optical characteristics.

TABLE 5 shows the values of the imaging lens assembly LA in relevant tothe conditions (1) to (5) according to both the first embodiment and thesecond embodiment. Moreover, in TABLE 5, the unit of the value 2ω isdegree (°), and the units of the values f, f1, f2, f3, f4, f5, TTL, LBand IH are millimeter (mm).

TABLE 5 Embodiment 1 Embodiment 2 Formulae R1/R2 0.148 0.151 Formula (1)R3/R4 −1.437 −1.424 Formula (2) R9/R10 −0.567 −0.571 Formula (3) f3/f14.263 12.694 Formula (4) R5/R6 0.740 0.731 Formula (5) Fno 2.20 2.20 2ω80.8 80.8 TTL/IH 1.270 1.272 f 3.363 3.612 f1 2.364 2.364 f2 −4.890−4.875 f3 47.967 45.851 f4 2.753 2.750 f5 −2.008 −2.014 TTL 3.735 3.739LB 0.898 0.898 IH 2.940 2.940

In summary, the imaging lens assembly LA as provided in the presentdisclosure has good optical characteristic, high luminous flux as wellas an ultra-thin profile, and moreover, the imaging lens assembly LAsatisfies the following parameter requirements: TTL/IH≦1.30, view angle2ω≧80°, and Fno≦2.2. Therefore, the imaging lens assembly LA isapplicable to a digital camera of a mobile phone or a WEB camera, whichuses CCD imaging components or CMOS imaging components with highresolution.

It is to be understood, however, that even though numerouscharacteristics and advantages of the present embodiment have been setforth in the foregoing description, together with details of thestructures and functions of the embodiment, the disclosure isillustrative only, and changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the invention to the full extent indicated by the broad generalmeaning of the terms in which the appended claims are expressed.

What is claimed is:
 1. A imaging lens assembly comprising: a first lenswith positive refractive power; a second lens with negative refractivepower; a third lens with positive refractive power; a forth lens withpositive refractive power; and a fifth lens with negative refractivepower; wherein the first lens, the second lens, the third lens, theforth lens and the fifth lens are arranged in sequence from the objectside to the image side, and satisfy following conditions (1) to (3):0.08≦R1/R2≦0.25  (1)−5.00≦R3/R4≦−0.30  (2)−1.50≦R9/R10≦−0.30  (3) wherein R1 is the curvature radius of the objectside of the first lens; R2 is the curvature radius of the image side ofthe first lens; R3 is the curvature radius of the object side of thesecond lens; R4 is the curvature radius of the image side of the secondlens; R9 is the curvature radius of the object side of the fifth lens;and R10 is the curvature radius of the image side of the fifth lens. 2.The imaging lens assembly of claim 1, further satisfying the followingcondition (4):10.00≦f3/f≦70.00  (4) wherein f is the focal length of the imaging lensassembly; and f3 is the focal length of the third lens.
 3. The imaginglens assembly of claim 1, further satisfying the following condition(5):0.65≦R5/R6≦1.05  (5) wherein R5 is the curvature radius of the objectside of the third lens; and R6 is the curvature radius of the image sideof the third lens.